Jet Lag
What is Jet Lag?
Jet lag is a temporary physiological condition caused by rapid long-distance travel across multiple time zones. When you cross several time zones quickly, your body's internal clock (circadian rhythm) remains synchronised to your home timezone while your environment operates on a completely different schedule. The result is fatigue, insomnia, difficulty concentrating, digestive disruption, and general disorientation.
The severity depends on the number of time zones crossed, the direction of travel (eastward travel tends to cause more severe jet lag as it requires advancing your clock), and individual factors like age and prior sleep debt. Recovery typically takes one day per time zone crossed, though experienced travellers develop strategies to accelerate adjustment: strategic light exposure, melatonin supplementation, and immediately adopting the local sleep schedule upon arrival.
Example of Jet Lag
Sofia flew from Barcelona to Tokyo — a nine-hour time difference — arriving Tuesday morning. By day two she felt fairly functional. But on day three, jet lag hit properly: she woke at 2am fully alert, then crashed at 3pm local time, exactly when she'd planned to visit Tsukiji. She sat on a bench eating a tamagoyaki skewer, trying not to fall asleep standing up.